Through a simple comparison I tested the highest CpS possible whilst AFK wrinkler grinding.
Using the most obvious combination of Holobore, Mokalsium and Jeremy, I found the highest CpS is from Mokalsium in diamond to boost milk, Holobore in ruby to boost base CpS and finally Jeremy in jade to boost building CpS.
These are the most obvious answer but possibly not the most effective. But for my case it's fine, I don't need faster lump generation.
Once you're ready to ascend or pop wrinklers, simply swap Skruuia into diamond slot and you'll get all the extra cookies from that boost since it just boosts the pop amount.
Contributors are welcome to point out flaws or other combinations and their effectiveness.